Currently, the liquid crystal display panel develops rapidly toward large size and high resolution. As shown in FIG. 1, for a large size liquid crystal display device, the chips packaged with scan driving circuits therein are usually arranged on the left and right sides of the display panel, for providing scanning signals to the display panel through scanning wirings connected thereto. As the scanning wiring itself has a certain impedance, the waveform of the scanning signal, which is inputted from the left and right sides of the display panel, will suffer from distortion to a certain extent when the scanning signal arrives at the middle part of the display panel. Generally speaking, the larger the size of the display panel, the more serious the distortion of the scanning signal, and the lower the charging rate of the pixel points in the middle part of the display panel. This leads to a phenomenon that the brightness is relatively high at the left and right sides of the display panel but is relatively low at the middle part of the display panel in low gray-scale display. Such phenomenon of non-uniform brightness is usually called “becoming white near the left and right sides”.
Therefore, how to improve the phenomenon of “becoming white near the left and right sides” is an important subject to raise the picture quality of the liquid crystal display panel.